Current situation

The rainfall received in South London at the beginning and end of January resulted in groundwater levels increasing more sharply after those events. However, after receiving a less significant amount of rain in the first half of February, groundwater levels are now increasing at lower rates.

Groundwater levels are now above normal for this time of the year in South London.

Short term forecast 

If the drier conditions continue, the slowdown of the rise in groundwater levels will likely continue until the end of February. Some spells of rain are predicted, but no heavy rainfall is currently expected in the south east.

Longer term forecast 

Some unsettled weather and spells of rain are predicted for the first half of March. However, drier and brighter periods are also expected to occur in between wetter days.

The levels are not currently predicted to get high enough to cause any flooding. The likelihood of flooding to occur in March and possibly April is dependent on the amount and intensity of rainfall we receive. In addition to the rainfall, the onset and frequency of spring-like (that is, bright) conditions can also influence the likelihood of flooding. If we receive higher than average rainfall from the latter end of February onwards, groundwater flooding of basements and low-lying land could still occur.

This would also result in winter bournes (rivers which flow in winter because of high groundwater levels) such as the Caterham Bourne beginning to flow.

Graph showing the trend of groundwater levels since April 2023 at Woldingham Observation Borehole in South London overlying a background of colour banding indicating relatively high and low conditions. Levels are above normal for this time of the year on 17 February 2025.

What the Environment Agency is doing 

We will continue to monitor groundwater levels across South London and provide situation report updates throughout the remainder of this winter. The next report will be published next month unless the situation changes significantly.

We will take evidence-based decisions. If conditions deteriorate, we will notify our partners (including lead local flood authorities and water companies). We will also actively engage with our partners to help them prepare for incident response.

Actions and advice

There is practical advice on what to do before, during and after groundwater flooding, and further guidance about groundwater flooding, how it might affect you and what to do.

Next update

We will continue to monitor groundwater levels closely and we will provide a further update next month unless there are any significant changes.

Further information

You can view:

• groundwater situation reports by area

• flood alerts

• river and sea levels in England

• water situation: area monthly reports for England 2024

Contacts

If you have any questions, please email enquiries@environment-agency.gov.uk.

The Environment Agency offers free Groundwater Flood Alerts. You can:

• call Floodline on 0345 988 1188
• visit GOV.UK for current flood alerts and warnings
• follow @EnvAgencySE and #floodaware on Twitter for the latest flood outlook